Stolen Fireworks AI Key Led to Cursor Data Breach and Trojanized Claude Code Extension

The compromise of Anthropic's official Claude Code extension on Cursor's extension marketplace was the result of the theft of an access key that was exposed in the wake of a breach targeting Fireworks AI. "An attacker obtained an access key we had issued to Fireworks," Cursor said in a Friday update. "The key was exposed by Fireworks, and the attacker used it to copy data from a read-only